package com.lyf.common.utils;

/**
 * @author lyf
 * @date 2020/11/19
 */
public class GeoUtils {
    /**
     * 默认地球半径/赤道半径(单位m)
     */
    private static double EARTH_RADIUS = 6378.137;

    /**
     * 转化为弧度(rad)
     */
    private static double rad(double d) {
        return d * Math.PI / 180.0;
    }

    /**
     * @param lon1 第一点的精度
     * @param lat1 第一点的纬度
     * @param lon2 第二点的精度
     * @param lat2 第二点的纬度
     * @return 返回的距离，单位m
     */
    public static double getDistance(double lon1, double lat1, double lon2, double lat2) {
        double radLat1 = rad(lat1);
        double radLat2 = rad(lat2);
        double a = radLat1 - radLat2;
        double b = rad(lon1) - rad(lon2);
        double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2), 2) + Math.cos(radLat1)
                * Math.cos(radLat2) * Math.pow(Math.sin(b / 2), 2)));
        s = s * EARTH_RADIUS;
        s = Math.round(s * 10000d) / 10000d;
        s = s * 1000d;
        return s;
    }

    public static void main(String[] args) {
        double lon1 = Double.valueOf("113.966986");
        double lat1 = Double.valueOf("22.78912");
        double lon2 = Double.valueOf("113.961488");
        double lat2 = Double.valueOf("22.779207");
        double d = getDistance(lon1, lat1, lon2, lat2);
        System.out.println(d);
    }
}
